these four walls
idiomPart ofwall
these four walls — idiom
1. used to talk about keeping a secret within a small, private group, implying that
1.idiom
Definition
used to talk about keeping a secret within a small, private group, implying that the information must not be told to anyone outside that space.
Example
Please keep what I said within these four walls — do not tell anyone else.
What is discussed in this room stays within these four walls, understood?